We look at the division of 66174105 by 72 
The aim is to understand the frequency of 72 in 66174105.

On to step 1:
The number 72 fits into 6 0 times, leaving a remainder of 6.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Deduct 0 from 6 and we're left with 6.
Take the next digit (6) from the dividend and append it to 6, then repeat: 66 / 72

Moving on to step 2:
When dividing 66 by 72, we get 0 with a remainder of 66.
The next digit of our result is 0. 
Result so far: 0.0
The remainder is 66 after subtracting 0 from 66.
Fetch the next digit (1) from the dividend, attach it to 66 and continue: 661 / 72

On to step 3:
The number 72 fits into 661 9 times, leaving a remainder of 13.
Use 9 as the next digit of our solution. 
Result so far: 9.0
Deduct 648 from 661 and we're left with 13.
Bring next digit (7) of the dividend behind the 13 and repeat the process: 137 / 72

Let's proceed to step 4:
The number 72 fits into 137 1 times, leaving a remainder of 65.
The next digit of our result is 1. 
Result so far: 91.0
The remainder is 65 after subtracting 72 from 137.
Take the next digit (4) from the dividend and append it to 65, then repeat: 654 / 72

On to step 5:
72 goes into 654 9 times with a remainder of 6.
The number 9 becomes the next digit in our result. 
Result so far: 919.0
If we take 648 away from 654, we end up with 6.
Append the next digit (1) from the dividend to 6 and continue with: 61 / 72

Going ahead to step 6:
72 can be fit into 61 0 times, resulting in a remainder of 61.
Use 0 as the next digit of our solution. 
Result so far: 9190.0
Deduct 0 from 61 and we're left with 61.
Include the next digit (0) from the dividend after 61, then repeat: 610 / 72

Moving on to step 7:
72 goes into 610 8 times with a remainder of 34.
Record the quotient 8 as the next digit in the result. 
Result so far: 91908.0
Subtract 576 from 610 to get 34.
Fetch the next digit (5) from the dividend, attach it to 34 and continue: 345 / 72

On to step 8:
72 goes into 345 4 times with a remainder of 57.
The number 4 becomes the next digit in our result. 
Result so far: 919084.0
Subtract 288 from 345 to get 57.
Since there are no more digits in the dividend, we add a zero to the remainder making it 570, and continue the process.

Advancing to step 9:
If we divide 570 by 72, we get 7 and a remainder of 66.
Put 7 as the next digit of the answer. 
Result so far: 919084.7
Deduct 504 from 570 and we're left with 66.
Since there are no more digits in the dividend, we add a zero to the remainder making it 660, and continue the process.

Let's proceed to step 10:
When dividing 660 by 72, we get 9 with a remainder of 12.
The next digit of our result is 9. 
Result so far: 919084.79
Subtracting 648 from 660 leaves us with 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

Step 11:
When dividing 120 by 72, we get 1 with a remainder of 48.
Write down 1 as next digit of the result. 
Result so far: 919084.791
If we take 72 away from 120, we end up with 48.
Since there are no more digits in the dividend, we add a zero to the remainder making it 480, and continue the process.

Let's proceed to step 12:
If we divide 480 by 72, we get 6 and a remainder of 48.
Write down 6 as next digit of the result. 
Result so far: 919084.7916
If we take 432 away from 480, we end up with 48.
Since there are no more digits in the dividend, we add a zero to the remainder making it 480, and continue the process.

Going ahead to step 13:
72 goes into 480 6 times with a remainder of 48.
Use 6 as the next digit of our solution. 
Result so far: 919084.79166
Subtract 432 from 480 to get 48.
Since there are no more digits in the dividend, we add a zero to the remainder making it 480, and continue the process.

After the division, we end up with 919084.79166 and a remainder of 4.8e-05.